We present studies of the Extreme Ultraviolet (EUV) emission in the Fornax cluster of galaxies; a relatively nearby well-studied cluster with X-ray emitting cluster gas and a very large radio source. We examine both the large-scale (∼ size of the X-ray emitting cluster gas), and the small-scale (< arc min) emission. We find that this cluster has large-scale diffuse EUV emission. However, at the...

The purpose of this study was to evaluate the use of digital x-ray imaging detectors for the measurement of diagnostic x-ray tube focal spot size using a slit camera. Slit camera images of two focal spots for a radiographic x-ray tube were acquired with direct-exposure film (DF) (as specified by the National Electrical Manufacturers Association [NEMA] Standards Publication No. XR 5, 1992), comp...

Flat-panel X-ray detectors for fluoroscopy represent a modern imaging equipment that is being implemented in paediatric cardiac catheterisation laboratories. Infants and children represent a group of patients with a high radiosensitivity. A survey of 273 (126 diagnostic and 147 therapeutic) paediatric catheterisations was performed to investigate the radiation doses delivered by the new X-ray s...

First images are presented from tests of a semi-insulating gallium arsenide X-ray imaging detector, flip-chip bonded to a current integrating CMOS readout chip. The detector is designed for applications in synchrotron X-ray imaging. The X-ray sensing part of the detector consists of a 150 mm thick GaAs photodiode containing an array of 92 100 pixels, each 150mm by 150 mm in size. Operating the ...

The understanding of the image properties produced by a medical imaging system is critical to effective interpretation of the diagnostic images they produce. Quantitative analysis of image properties like spatial resolution can be complex in computed tomography when advanced model-based reconstruction methods like penalized-likelihood estimation are used since spatial resolution is dependent on...

A system for cone-beam computed tomography (CBCT) based on a flat-panel imager (FPI) is used to examine the magnitude and effects of x-ray scatter in FPI-CBCT volume reconstructions. The system is being developed for application in image-guided therapies and has previously demonstrated spatial resolution and soft-tissue visibility comparable or superior to a conventional CT scanner under condit...

Introduction: Unfolding X-ray spectrum is a powerful tool for quality control of X-ray tubes. Generally, the acquisition of the X-ray spectrum in diagnostic radiology departments is complicated and difficult due to high photon flux. Measurement of x ray spectra using radiation detectors could not be performed accurately, because of the pulse pile up. Therefore, indirect methods...

In the last ten to fifteen years there has been much research in using amorphous and polycrystalline semiconductors as x-ray photoconductors in various x-ray image sensor applications, most notably in flat panel x-ray imagers (FPXIs). We first outline the essential requirements for an ideal large area photoconductor for use in a FPXI, and discuss how some of the current amorphous and polycrysta...

Flat-panel cone-beam CT (CBCT) has been applied clinically in a number of high-resolution applications. Increasing geometric magnification can potentially improve resolution, but also increases blur due to an extended x-ray focal-spot. We present a shift-variant focal-spot blur model and incorporate it into a model-based iterative-reconstruction algorithm. We apply this algorithm to simulation ...

The CMOS panel sensors developed for detecting high quality X-ray images, feature large formatted active area and high resolution. The purpose of this study was to assess the performances of imager have a diagonal size of 6.9 inches (non-tiled monolithic chip) and made of monocrystalline silicon optimized for use in digital radiography associated with two kind of thallium doped cesium iodide sc...